Fuel tank filler/vent

[72stroker]

I installed a poly tank from LMC. I havent had any issues until I topped off the fuel tank. I must of filled too much, because when I refueled. I couldnt get any fuel into the tank. I drained the vent line, but havent tried to refuel yet. My guess is it will work.
Is there some type of check valve that wont allow fuel to go into the vent, Do I need a vented or non vented cap?

[cdowns]

trick is to have vent line higher than tank

[72stroker]

It is higher, I used a filler next with the vent line built in, and ran a hose down to the tank.
I think the problem came when I filled it into the filler neck, and it also went up the vent hose.

[caja_larga]

your vent line has a ball in it for roll over. It could have stuck to the top not letting it vent.

[72stroker]

I dont have a rollover valve.
I took the hose off the vent and it was full of fuel.

[2bits]

When I installed my Blazer tank every once in a while it will do the same thing. I don't know what the reason for it is either, so while this is not much help mayber try again now that it is a different day and it might work. Worked for me It doesn't do it that often so when it happens, I just fill up some other time.

[UltraBlue71]

Why wouldnt the gas run out of the vent line as the fuel level in the tank dropped? Do you have a sag in the line or a U shape where the fuel was able to collect and remain?

[cdowns]

if the fuel is staying in the line theres something holding it there //i'd take the hose off and run a piece of coathanger down to see whwere the obstrucyion is

[72stroker]

Ultrablue I think you are on to it. there was a little bit of a sag.
The fuel cant drain if the air has no place to go. I took the line off blew the fuel out and reinstalled. Fueled up this morning and it worked.
I was just wondering if there is a valve that would prevent it from happening again.

[UltraBlue71]

Glad you figured it out, the way these trucks use gas a fella cant be spending all his time at the pumps! You have probably already tried repositioning the vent line to take the sag out other than that I dont know of a valve or vent that would help you out, a check valve maybe, depending on the design and location, but why overcomplicate it, I bet if your vent line is positioned correctly it will remained fixed. -Cory